


The King Has Fallen

by amarillogrande



Series: A Dangerous Game [2]
Category: Supernatural
Genre: Angst, Castiel tries to cure Dean basically, Demon Cure, Demon Dean, Demon Dean Winchester, M/M, after 9x23, i dont even know
Language: English
Status: Completed
Published: 2014-05-28
Updated: 2014-05-28
Packaged: 2018-01-26 20:30:41
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 1
Words: 3,802
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1701542
Author URL: https://archiveofourown.org/users/amarillogrande/pseuds/amarillogrande
Summary: <blockquote class="userstuff">
              <p>Castiel finds Dean, and knowing he's living on borrowed time, attempts to cure Dean before he returns him to Sam, and Sam will never have to know what his brother had been. His one last gift to the Winchesters.</p>
            </blockquote>





	The King Has Fallen

**Author's Note:**

> Tried my hand at writing Demon!Dean.  
> I have to say, I have no idea which way they're gonna go with this. I'm torn between wanted dorky Demon!Dean trying to hunt with Sam and Cas and failing miserably, and having Dean be the scary new Big Bad and go all badass on everyone. So here's one version of that.
> 
> Tumblr: [x](http://chevrolangels.tumblr.com/post/87053734348/castiel-finds-dean-and-knowing-hes-living-on)  
> 

First Injection

9:05 pm

 

Castiel approaches the devil’s trap with trepidation.

Dean is awake now, watching him with cold eyes. Still green.

The space between them is long and dark, Castiel struggling forward between the silent pews, unable to drag his eyes away from the man in front of him.

“Castiel.”

No. Not a man. 

Dean stretches languidly, as much as the chains will let him, and he yawns, settling back to watch.

“Hey there, angel.”

Castiel ignores his words, trying to focus on the task at hand.

“To what do I owe the pleasure?”

Dean’s words are harsh and mesmerizing, sounding so familiar, yet so different—everything about this horrible and ruined. Castiel knows this is his friend, his best friend, chained and locked in by spells and entrapments, when Castiel wishes it was just Dean—the real Dean, the  _human_ Dean—anything but this twisted scrap of a soul, sneering at him with harsh black words, voice poisonous and dark in the cold night air of the church.

Castiel pulls the syringes from their container, setting them on a table, just outside the edge of the sigil marked on the floor.

Dean’s eyes fall upon the needles, and then he laughs, tipping his head back in a cruel imitation of his normal laughter, raucous mirth tinged with a vicious edge Castiel doesn’t think he’s ever heard before.

“Oh, oh, oh.”

Castiel is silent as he preps the syringes, checking the volume, squinting at the content contained in plastic.

“Cas-ti-el.”

Dean grins at him.

“You gonna try and cure me?”

Castiel doesn’t respond. He picks up the first syringe, filled with his own blood, and he offers up another prayer, that it will be enough. Pure enough.

“Won’t work, darlin’,” Dean seethes. “I’m not your average run-of-the-mill demon.”

Both of their eyes fall to it, unwittingly. The Mark, burning bright in his forearm, harsh and red.

Castiel tries not to listen. He inches forward, walking cautiously. Dean might be chained, but he is still unbelievably dangerous.

As he approaches, the humorous expression on Dean’s face immediately twists into a snarl, those beautiful green eyes snapping black.

“You touch me, and I’ll rip you apart,” he snarls, yanking at his restraints.

Castiel ignores him, reaching out and taking a grip of Dean’s hair. But he rips from the touch and snaps at him—teeth biting down on air, just short of Castiel’s fingers.

Castiel snatches his hand back, panting. Dean watches him through hooded eyes.

“I’m not that easy, sweetheart.”

He bares his teeth again, sneering at him.

“Can’t catch me, I’m the gingerbread man,” he singsongs, taunting him.

Castiel sets his jaw, his lips tightening in a thin line. He summons his power, calling upon the last vestiges of it, and he feels its strength settle in his bones. He twirls his fingers and Dean’s head forcibly snaps to the side, baring his neck to Castiel. Dean growls and fights against it, but Castiel’s grace holds him firm. He approaches quickly, placing a strong hand on his cheek and slipping the syringe to his neck, into the pulsing vein, pressing down until the blood disappears. Dean hisses at him, even as Castiel holds him down.

“Ain’t gonna work.”

Castiel’s hand falls, gripping the empty syringe with shaking fingers.

“You can’t fight this,  _Castiel_ ,” Dean snarls as he walks away from him, back turned.

“You know it!”

 

He screams at his retreating form.

“You can’t fight  _me!”_

 

Second Injection

10:09 pm

 

“Fuck you.”

Castiel doesn’t speak as Dean hurls insults at him, shouting and yelling all the way across the church.

“You’re an abomination, you twisted piece of shit—you’re nothing, you’ll always be nothing—“

Castiel yanks his head to the side, forcibly sliding down on the plunger, Dean’s voice hissing in his ears.

“You think  _your_  blood will be enough? A sorry excuse for an angel with clipped wings—”

Castiel concentrates, ignoring the pounding in his head.

But suddenly, Dean’s anger seems to leave him, and he calms in his chair, settling into a cool stillness. Which, if anything, scares Castiel more.

“So. What’s the plan?” Dean asks calmly. “You gonna give me up as a peace offering? To Sam?”

Castiel doesn’t respond. Even if Dean seems to cut through everything and dig straight to the heart of the matter—knowing instinctively why Castiel is doing this, he can’t answer him.

“Ohhh. Now I see why.”

Dean glances at him from the corner of his eye as Castiel continues to focus on the disappearing blood in the syringe’s vacuum.

“You think this will be your salvation.”

Castiel’s blood runs cold.

“You know you don’t have anything.”

Dean looks up at him lazily, lips curving into a dangerous smirk.

“Nothing beside the two of us, and you’re going to die. Soon, too, I expect.”

His voice is softer now. Menacing.

“And this is gonna be your last act, huh? Your one last redemption before that borrowed grace fizzles up and kills you for good?”

Castiel takes a steadying breath.

“Guess I’ll take that as a yes.”

Dean watches him with violent eyes.

“Your last gift,” he sneers. “But you know what? Sam doesn’t care. He doesn’t care about you. Only about me.”

His breath is hot and meaty on Castiel's face—sulfur and blood colliding with Dean’s natural aura—the one that still ached of righteousness, of hope and strength and virtue. But Castiel can still see the echoes of Dean's soul—little green wisps and tugs of light, bleeding through, desperately struggling against the vile black thing cloaked around it. 

Dean continues to hiss at him.

“We don’t need you. We never needed you. Because you’re  _nothing_ , Castiel.”

Castiel rips the needle from his neck, not caring when his blood dribbles from the mark. He can only see Dean snarling at him, teeth gnashing as he struggles against his bonds.

“Nothing to us, nothing to  _me.”_

Those last three words hurt more than Castiel would care to admit.

 

Third Injection

11:05 pm

 

Castiel can’t breathe as he makes the walk from the church doors to the altar.

It’s harder this time—it’s harder every time—but having Dean watch him is even more painful, knowing it’s not really Dean.

He prepares the syringe, trembling fingers betraying him as he desperately tries to ignore the thing in the chair. It screams at him, sneering harsh words in his face.

“I know why you’re doing this, Castiel.  _Cas_.”

Castiel closes his eyes, breathing hard.

“I know why you want this. I’ve seen the way you stare.”

Castiel grips the needle in his hand so hard it starts to hurt.

Dean’s voice hisses in and around his ears, digging into him, pulling up those emotions and thoughts Castiel had sworn to bury.

“Am I your type now?” He whispers.

Castiel snaps his eyes to Dean’s, still that beautiful green, and he grins, his chained hands gripping at the chair beneath him.

“Guess I am.”

His eyes slide to black again, and Castiel wants to jerk back, wants to run away.

But he doesn’t. He can’t.

“You always did seem to have a thing for demons.”

Castiel jerks Dean’s head to the side, slipping in the needle and pressing down ruthlessly, but Dean won’t stay quiet.

“Am I like her? Do I look like her to you?”

Castiel shuts it out, wanting not to hear. He successfully manages to block it out for a while, but then Dean says—

“I used to be afraid. Used to be afraid of what I was, but now I realize.”

Castiel pulls back, staring at him.

“This is who I am,” Dean snarls, glaring at him from those horrible eyes, struggling and fighting against the warded chains holding him down.

“I never knew, I never knew how  _good_  it could be.”

He arches back, sending a pealing laugh to the rafters.

“I’ve been fighting the darkness my whole life, but I know now.” He laughs again. “I know that this—is— _me._ ”

Castiel summons the strength to speak.

“This is not you,” he hushes out.

Dean smiles devilishly at him, the dim light of the church reflecting off the oil-slick color of his eyes.

“This is me, baby,” he purrs. “New and improved.”

Castiel acts on instinct—darting forward and seizing his throat, but Dean just laughs at that, spitting harsh words in his face.

“Did I get the infamous stoic Castiel to snap? Well, gold star to me—“

Castiel snarls at him, tightening his grip.

“Dean is a man marked by Heaven. He is worth so much more than this,” he hisses.

“Ooh,  _possessive_ ,” the thing sneers. “I like it.”

Castiel realizes the danger and quickly draws back, shaking his head. Stay calm. Detached. Emotions only complicate things. Dean told him that once.

 

“He was always so worthless, wasn’t he?”

Castiel freezes.

“So full of loathing and fear—“

Castiel turns slowly, fire burning in his eyes.

“But I’m free of that now.”

Dean spreads his hands, his smile sharp and wide. The light glints off his teeth.

“I know this is what I am,  _who_ I am.”

He drops his voice low.

“And I’m better than he could ever be.”

 

Castiel doesn’t even remember deciding to do it—but he punches him, striking him hard across the face. Dean breathes harshly, dragging his face back to center, focusing on Castiel’s wild eyes.

“Fuck you,” Castiel snarls.

Dean spits red. It dribbles down the front of his shirt.

He smiles through blood-stained teeth.

“You’re sexy when you swear.”

 

Castiel turns on his heel and exits the church without another word.

 

Fourth Injection

12:15 am

 

Castiel holds his breath when he slides the syringe into Dean’s neck.

He sinks his eyes closed, letting out a little moan.

“Yeah, baby, stick it in,” he whispers.

Castiel pulls back silently, refusing to engage him. Dean tugs a little on his restraints, tilting his head up toward Castiel’s own.

“Thought about me all tied up before, haven’t you?”

Castiel turns away from him, determined to ignore the horrible thing masquerading with Dean’s face.

He checks the row of syringes, deciding to prepare the next one now, if only to get it over with.

“Think about me all the time, don’t you.”

This time it’s not a question. Despite his promises to himself, Castiel turns, ready to retaliate—but Dean’s eyes stop him cold.

Not black, not hard.

That still, perfect green—harsh and gentle all at once, trapping him and pulling him in.

“I know you have.”

The impersonation of Dean licks his lips, fixing him with those dangerous eyes.

“I can see it in your mind,” he murmurs. Castiel thinks he stops breathing.

Dean slides forward on his chair, speaking slyly, that hypnotic voice of his, hands reaching out in the imitation of affection, eyes bright and dark.

“Can see it so clearly,” he breathes. “Because you’re barely an angel now, aren’t you—“

He moves forward in his seat, so close now—so close…

“I know you did, I know you thought about me when you were human,” Dean sneers. “Know you fought against it, but eventually gave in—know you struggled against yourself in the dead of night, calling out my name.”

Castiel pulls away wordlessly, yanking himself back down the aisle, fighting back the tears.

“Too bad I never felt the same way,” Dean’s voice calls.

Castiel shuts the church doors, falling against them, tears dripping silent and thick against the heavy wood.

 

Fifth Injection

1:43am

 

Castiel is nervous as he makes the trek up the aisle once again.

Not only because he has to face Dean again, but because he fell asleep—his dwindling grace and the loss of blood were taking their toll on him, and he had passed out in a moment of weakness, and now he was almost thirty minutes behind schedule. He hopes it does not affect the process.

“Heya, Cas.”

Castiel almost doesn’t hear him.

But Dean doesn’t struggle or flinch at all this time. Castiel slides the needle in cleanly, and when he’s done, those eyes are on him again.

Castiel avoids the gaze, instead staring determinedly at his work. But his eyes drift, down to Dean's chest, and he sees dried blood, crusting just underneath the collar of his shirt.

Dean sees the gaze, and his eyes widen.

“No—don’t—“

Castiel yanks it aside, exposing the wound there.

It’s fatal—harsh and bright with blood. Dean would almost certainly be dead if not for…

Well.

Dean avoids his eyes, shifting a little under the intense scrutiny Castiel is fixing on him.

“Some asshole with a gun thought he’d take a stranger’s wallet,” he says, attempting to laugh.

“So I took his intestines.”

Castiel ignores his words and screws his face up in concentration, reaching a hand out. Dean darts his gaze up to him, eyes hard.

“What’re you—“

Castiel places a hand to the spot, ignoring the feeling of tender, raw flesh beneath his fingers. He sends out his grace, mending the injury, healing the wound, knitting the skin together.

But as soon as he does, he stumbles back, the effort of the healing taking its toll.

Dean snarls.

“Dammit, Cas—“

Castiel braces himself, hands on knees, panting.

“Why the fuck did you do that, you asshole!”           

Dean is glaring at him, fists balled in anger.

Castiel regains his breath, meeting his furious gaze.

“You would have died,” he spits. “If you were human.”

Dean snarls.

“Good thing I’m not human.”

Castiel’s back tenses. He straightens and turns away from him, breathing harshly through his nose. But Dean’s voice stops him.

“Why are you doing this?” Dean asks. Castiel almost didn't hear him.

He turns, looking at him from the aisle of the old ruined church.

Castiel answers with two words.

 

“For you.”

 

Sixth Injection

2:41 am

 

Castiel wipes his forehead, his skin pale and clammy.

“Cas, you’re not okay.”

Dean’s voice sounds clear, concerned even, but Castiel is wary.

“Why do you care?”

Dean swallows, tugging at his restraints a little.

“Don’t wanna end up tied to this chair forever,” he lies, adding an indifferent chuckle.

Cas just shakes his head to clear it, stepping up, his footsteps slow and unsteady. Dean watches him.

“You got your wings on? Now that Heaven ain’t boarded up?”

Cas doesn’t look at him as he prepares the next syringe.

“Angels can fly again, yes.” He answers curtly. Dean shifts in the chair.

“But you can’t.”

Cas keeps fiddling with the needle.

“No,” he admits.

He turns to Dean, reaching out to take a grip of his hair, but he stumbles, and Dean grabs his wrist, steadying him.

“Cas, you’re gonna die,” he says softly.

Cas rips his hand from his grip, glaring down at him. His eyes are hard.

“Your threats don’t scare me.”

Dean scrambles.

“No—that’s not what I—Cas—“

Cas cuts him off, pulling his head to the side and quickly slipping the needle in, swift and efficient. Dean exhales harshly as he feels it hit his system, his head cleared with a rush of something he can’t quite describe.

His head droops as Cas cleans up, but he manages the effort to look up, to speak again.

“Don’t do this, Cas.”

He doesn’t look at him, but Dean sees his hands pause.

“I can help,” Dean whispers. “The power I got—I can help you. You can’t heal me at the cost of your own life.”

Cas doesn’t respond. Dean snarls in frustration.

“If not me, then who? The other angels—Don’t they give a damn about you? Fearless leader?  _Commander_?”

Cas grips the edge of the table with shaking fingers. Dean can tell he’s struggling with the effort to stand.

“Stealing another’s grace is an abomination,” he whispers. His face is full of pain. Dean wants to reach out and touch him.

“You had to, Cas.” He says softly. “Don’t they know that?”

Castiel straightens, his eyes once again callous and cold.

“I don’t think that crossed their minds.”

 

Seventh Injection

3:32 am

 

Castiel’s steps are heavy, slow. It’s a labor for every movement forward, but Dean doesn’t move. He waits for him in the chair, eyes fixed on him the whole time as he makes the long way from the church doors to the devil’s trap painted at the base of the altar.

Castiel reaches the edge and picks up the second-to-last of the syringes, his fingers shaking a little. Dean doesn’t say anything, merely tilts his head to the side, willingly baring his neck.

Castiel takes a deep breath.

He steps forward, placing a gentle hand on Dean’s chin. He closes his eyes at that, and Castiel places the tip of his needle to his neck. Dean sighs, letting out his breath with a soft sound. Castiel holds him, pressing down carefully on the plunger.

Dean arches back a little as the blood hits his veins, and he groans, softly, so softly Castiel might have missed it, and when the syringe empties and the last of the liquid seeps into his veins, Dean sinks, his whole body loosening. Castiel sinks back too, the needle loose in his fingers.

He drops it, falling back on his heels, struggling to stay standing.

Then there’s a hand on his waist, steadying him.

Before he knows it, Dean’s pulling him in, and Castiel falls, sinking into his arms.

The handcuffs stop him a little, but Dean does the best he can with his limited mobility. He places gentle hands on Castiel’s cheeks, dragging him down.

And when Dean kisses him, Castiel’s mind blanks. Everything whites out, the fear, the trepidation—the pain in his aching body, the flares as his grace sparks and burns out—all forgotten. Dean slips a hand around his neck and Castiel pushes down into him, opening up his mouth and letting Dean slip his tongue inside, and he moans to feel it, feel what he’s been wanting for years. They heave together, Dean’s soft breath opening him up and pouring into him, filling him with a warmth and strength, unlike anything he’s ever known.

Castiel is lost. He tangles his hand into Dean’s hair, groaning against him, that kiss deepening, as their bodies press together, every inch of Dean beneath him hot, but strangely soft.

They break apart, but Dean doesn’t let him pull away. They hold still, foreheads touching, Dean’s lips inches from his own.

“Cas,” he breathes.

“Cas.”

Dean brushes his hands through Castiel’s hair almost reverently, eyes closed. They’re sharing the same air, breathing hard, everything forgotten. There’s only the two of them. Nothing else.

Castiel drifts his hands down Dean’s neck, his chest, finally settling on his arms. His fingers absentmindedly trace his skin, and he brushes over the raised red brand in Dean’s forearm.

Castiel's eyes snap open.

He jerks away from him, falling back hastily. Dean is looking at him desperately, something like pain crossing his face…

_No._

Castiel shakes his head.

_It’s not him, it’s not Dean, not the real Dean_

Castiel straightens, strengthening his resolve. His eyes harden and he stalks away from him, slamming the church door behind him.

 

Dean watches him go.

 

Then he fingers the key in his palm, the key he stole from Castiel’s pocket.

 

Eighth and final Injection

4:46 am

 

Castiel can barely see anymore.

The church in front of him is just blurs of color. He only knows the distance to Dean’s chair because he’s memorized it by now—and he takes unsteady steps forward, breathing heavily.

He falls, and throws out a hand, bracing himself on one of the pews.

_Please_

_Cas_

He hears a voice say.

He drops the syringe in his hesitation, in his clumsiness, but Dean is quiet and still as he picks it up slowly, and the final needle slides home, the last dose of blood in his veins.

Dean is staring at him, his mouth moving with unheard words.

Castiel’s breath hitches as he draws his knife, his vision shifting slightly. He places the blade in his hand, ignoring that almost-soothing voice.

He turns to him, repeating the spell in his mind.

“Exorcizamus te,” he starts hoarsely. “Omnis immunus spiri—spiritus.”

He slits his palm in a quick motion, the last faint traces of his grace struggling towards his hand to repair the damage.

“H-hanc animam redintegra—“

His vision hazes, and he wobbles, stepping back.

“Cas,” Dean begs, darting up.

 

Castiel blinks, uncomprehending.

Dean’s hands are turned upwards, reaching towards him. He’s standing, no longer bound to the chair.

His cuffs are undone.

“Dean,” Castiel breathes.

Dean takes hesitant steps forward, watching him.

Castiel can’t help it, he backs away, fingers shaking around his blade.

“You—“

He stares, uncomprehending. Dean advances with outstretched hands, his eyes soft.

Castiel gasps, choking back the bile in his throat.

“You—you want—“

He can’t finish.

Dean is close now, so close—and he curls his fingers around Castiel’s wrist, pulling his hand up towards him.

“Please,” he whispers.

Castiel stares. All he has to do is say the last few words. And then Dean will be whole. He will be himself again.

Castiel jerks his hand back, and Dean tries to reach out again—but he’s blocked—stopped by the edge of the devil’s trap. His face shows his frustration, his concern and fear as Castiel stares at him. He’s so close—so…damn…close…

Castiel doesn’t know when it happens, but suddenly the world is sliding around him—everything tilting backward and falling into the sky.

His back hits the cold ground. The knife falls from his bloody fingers.

The last thing he sees is Dean’s face, screaming for him.

 

Dean yells, throwing himself forward.

But the devil’s trap repels him—throwing him back, and he falls, panting. Cas is lying just outside the line, motionless. Dean shouts at him.

“CAS!”

He jerks against the barrier again, but gets nothing but searing pain in return.

“ _CASTIEL!_ ” He screams.

Cas doesn’t move.

Dean looks around desperately, everything in him whirling and storming. He feels hot anger burning under his skin, the fear, the hate—the desperation at being trapped here, unable to do anything—

He yells again and the church windows shatter around them, scattering the floor with glass.

Dean breathes heavily, his heart pounding.

He seizes on that power again and whirls his hand, eyes turning black with the force of his rage.

The ground shatters beneath them—the lines in the floor splintering. Dean growls and darts over the break, gathering up Castiel’s limp form in his arms.

“It’s okay, Cas, it’s okay,” he hushes out, cradling his head.

He pulls him in tighter, pressing soft kisses to his temple.

“If Heaven won’t save you,” he breathes.

 

“I will.”


End file.
